设
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、

是椭圆

的左、右焦点,

为直线

上一点,

是底角为

的等腰三角形,则

的离心率为( )
设P在x轴上的垂足为M,则

为等腰三角表,
所以

.
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相关习题
科目:高中数学
来源:不详
题型:解答题
已知圆

,椭圆

,若

的离心率为

,如果

相交于

两点,且线段

恰为圆

的直径,求直线

与椭圆

的方程。
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科目:高中数学
来源:不详
题型:解答题
设椭圆

的左、右顶点分别为

、

,点

在椭圆上且异于

、

两点,

为坐标原点.
(1)若直线

与

的斜率之积为

,求椭圆的离心率;
(2)对于由(1)得到的椭圆

,过点

的直线

交

轴于点

,交

轴于点

,若

,求直线

的斜率.
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科目:高中数学
来源:不详
题型:单选题

的周长是8,

,则顶点A的轨迹方程是( )
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科目:高中数学
来源:不详
题型:单选题
抛物线

与直线

交于两点

,其中点

的坐标是

,设抛物线的焦点为

,则

等于 ( )
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科目:高中数学
来源:不详
题型:填空题
如图所示,直线

与双曲线C:

的渐近线交于

两点,记

,

.任取双曲线C上的点

,若

(

、

),则

、

满足的一个等式是
.
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科目:高中数学
来源:不详
题型:填空题
在

中,

=90°,

=

.若以

、

为焦点的椭圆经过点

,则该椭圆的离心率

=
.
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